Fe3O4/SiO2/C nanocomposite as a high-performance Fenton-like catalyst in a neutral environment

The traditional Fenton system (Fe2+-H2O2) only works in an acidic environment and produces a large quantity of sludge. In this study, we reported that a Fe3O4/SiO2/C nanocomposite (FSCNC) could be used as a high-performance Fenton-like catalyst for the decoloration of methylene blue (MB). To prepare FSCNC, SiO2 was precipitated on Fe3O4 cores by the hydrolysis of tetraethyl orthosilicate, and the deposition of carbon was via the hydrothermal dehydrogenation of glucose. FSCNC showed much higher catalytic activity than naked Fe3O4 at a neutral pH of 7.5. Efficient decoloration of MB was achieved within 15 min in the FSCNC-H2O2 system. The FSCNC-H2O2 system worked well in the pH range of 3.5-9.5 and showed good resistance to radical scavengers tertiary butanol and ethanol. Higher H2O2 concentration and temperature were preferred to achieve faster kinetics. The regeneration of FSCNC was easily achieved by washing the catalyst and about 70% of the initial activity was retained after 8 cycles. The implication to the future applications of FSCNC as a Fenton-like catalyst is discussed.